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vni                       PANOCHTHUS AND  GL YPTODOW                    185
some Armadillos, the cervical vertebrae are at least partly fused.
The atlas is free, but the rest, or at any rate five of them, are
united. The last cervical is sometimes fused with the succeeding
dorsals; the latter are twelve in number, and are fused together
so far as concerns their centra and neural processes. The
succeeding region of the vertebral column includes seven to nine
lumbars, which are fused with the eight saerals; in this region the
neural processes are high, and there is thus produced a strong and
lofty ridge along the back, which forms a powerful support for
the carapace. The fore-limbs are shorter than the hind-limbs,
which latter are attached to an unusally massive pelvis. The
claws of the limbs are "blunt and almost hoof-like.
The heavy carapace consists of sculptured, five or six-sided
plates, which have no particular arrangement in the middle, but
towards the margins show indications of an arrangement in trans-
verse rows. The moderately long tail is also encircled by bony
skin-plates which are thorny above, or at least provided each with
a blunt upstanding process. It appears that outside this bony
system of scutes were horny epidermic scales, corresponding
exactly with the tesserae which they cover. There are apparently
a good many species of Gtyptodon.
In the allied genus PanochtJius the tail is rather longer, and
the bony rings which surround it, instead of being all movable
as in Grlyptodon, are at first so, but later, i.e. towards the end of
the tail, become welded into a single and massive piece. Both
feet are here four-toed, while in Gtyptodon the hind-feet are five-
toed and the fore-feet four-toed.
Daedicurus shows a further specialisation, in that the feet have
three and four digits respectively. The orbit too shows a
specialisation in being separated from the temporal fossa. The
descending process of the zygomatic arch is not so extraordinarily
exaggerated as it is in Glyptodon. It has the same terminal
tube of osseous scutes upon the tail. This creature seems to have
reached a length of about twelve feet.
PropalaeoJioplopfiorus is, unlike the great Armadillos that we
have hitherto dealt with, a small animal, not exceeding 2 feet
or so in length of carapace. A small alveolus on each side of the
premaxillae seems to suggest the former presence of an incisor
tooth; and it seems that the animal possesses both true molars
and premolars; for the first four of the eight teeth are much